Not sure if your conclusion isn't a bit premature......this chess game hasn't really started yet so it seems early to be speculating about Ackman's exit strategy.
Your comment......"it really isn't worth what he paid to anybody else".....well, some would argue the lack of share appreciation has been the problem for years. If shareholders are lucky, Ackman's involvement may force them toward the kind of performance they should be showing but seem consistently unable to deliver.
I'm not ready to rush to judgment that Ackman is trapped. Let's see what happens.....and whether you'll be proved right.
I find your term....."legitimate" shareholders....interesting. I'm unsure what would constitute legitimacy. But I'll assume you'd exclude the speculators and short-term traders. Even if Ackman could be considered a speculator....betting that his stake might enable him to force them to deliver better returns and formulate a compelling story about why anyone should want to hold their stock. It may be some time before we find out what kind of ideas he has, how they're received, and if he has indeed gotten his investors "trapped".
You make very good points (I gave you a thumbs up). But there are questions. What does Ackman know that management doesn't that wold improve performance? This is a very specialized industry; clearly they know it better then he does. Perhaps there is something that can be done quickly because I think the problem for him is time frame. I sense that Ackman's strategy (like other corporate "activists" ) is "hit and run". -- Drive the stock price up, get out and move on. Dead money is not an option for this type of investor.
That is why exit strategy is so imporant. I think he planned to buy a lot more than 9% + and I don't think he expected the poison pill. That is why I think he is stuck. Doesn't really own enough for a proxy fight (unless he gets many institutional buyers to back him). Owns too much to dump it on the market and anybody he sells his stock to will have the same issues he has now.